JP2023515016A - Lithium secondary battery and manufacturing method thereof - Google Patents

Abstract

TECHNICAL FIELD The present invention relates to a lithium secondary battery including a solid-liquid hybrid electrolyte membrane having a nonwoven fabric substrate layer and a porous structure layer, and a method for manufacturing the same. According to an embodiment of the present invention, it is possible to provide a lithium secondary battery including a solid-liquid hybrid electrolyte membrane with improved mechanical strength and ionic conductivity compared to conventional ones, and a method of manufacturing the same.

Description

TECHNICAL FIELD The present invention relates to a lithium secondary battery including a solid-liquid hybrid electrolyte membrane and a manufacturing method thereof. This application claims priority from Korean Patent Application No. 10-2020-0019877 filed Feb. 18, 2020.

Lithium secondary batteries are becoming more and more important as the use of vehicles, computers, and mobile terminals increases. In particular, there is a demand for the development of a lightweight lithium secondary battery that can provide a high energy density.

Such a lithium secondary battery is manufactured by inserting a liquid electrolyte after interposing a separation membrane between a positive electrode and a negative electrode, or by interposing a solid electrolyte membrane between a positive electrode and a negative electrode. manufacture.

However, since the lithium-ion battery using a liquid electrolyte has a structure in which the negative electrode and the positive electrode are separated by a separation membrane, if the separation membrane is damaged by deformation or external impact, a short circuit will occur, resulting in overheating or explosion. It can lead to danger.

On the other hand, a lithium secondary battery using a solid electrolyte has advantages such as increased battery safety and prevention of electrolyte leakage, improved battery reliability, and easy manufacturing of a thin battery. However, even if a solid electrolyte is used, there is still a need to develop a solid electrolyte membrane with high energy density and improved processability. In addition, in the case of solid electrolytes, there is a problem that the performance is deteriorated due to their low ionic conductivity, and the technical problem to be solved is that their mechanical strength is not high.

The present invention is intended to solve the above technical problems, and provides a solid-liquid phase hybrid electrolyte membrane that is thinner than the solid electrolyte membranes that are currently commercially available and that ensures ionic conductivity. An object of the present invention is to provide a lithium secondary battery comprising:

Another object of the present invention is to provide a lithium secondary battery including a solid-liquid hybrid electrolyte membrane having improved mechanical strength despite being thinner than the currently commercially available solid electrolyte membranes.

In addition, it is another object of the present invention to provide a lithium secondary battery including a solid-liquid hybrid electrolyte membrane that can be formed into a thin film and has an improved energy density per weight relative to the thickness compared to the solid electrolyte membranes that are currently commercially available. aim.

Meanwhile, other objects and advantages of the present invention will be understood from the following description. Also, the objects and advantages of the present invention can be achieved by means, methods or combinations thereof as indicated in the claims.

One aspect of the present invention provides a lithium secondary battery according to the following embodiments.

in particular,
A lithium secondary battery comprising a first electrode and a second electrode having opposite polarities, and a solid-liquid hybrid electrolyte membrane interposed between the first electrode and the second electrode,
The solid phase-liquid phase hybrid electrolyte membrane is
and a porous structure layer formed on at least one surface of the nonwoven fabric substrate layer, wherein the nonwoven fabric substrate layer has a microporous structure formed by a microstructure of polymer fibril. and solid polymer particles are dispersed or impregnated with the liquid electrolyte in the microporous structure,
The porous structure layer is in a state in which the solid polymer particles are filled and are in contact with each other, and a pore structure is formed between the solid polymer particles. surrounding the surface contact portion, or a part or the entire surface of the solid polymer particle,
The content of the liquid electrolyte is 50 to 70% by weight with respect to 100% by weight of the total content of the solid polymer particles and the liquid electrolyte,
The solid-liquid hybrid electrolyte membrane has an ionic conductivity of 1×10 ⁻⁵ to 1×10 ⁻¹ S/cm.

At this time, the polymer fibrils have an average diameter of 0.005 μm to 5 μm, and the nonwoven fabric substrate layer has pores with a diameter of 0.05 μm to 30 μm and a porosity of 50 to 80%. obtain.

At this time, the polymer fibrils are polyolefin, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyester, nylon, polyimide, polybenzoxazole, polytetrafluoroethylene, polyarylene ether sulfone, polyether ether ketone and It may be one or a mixture of two or more selected from the group consisting of these copolymers.

The solid polymer particles may be engineering plastic resins.

The solid polymer particles include polyphenylene oxide, polyetheretherketone, polyimide, polyamideimide, liquid crystal polymer, polyetherimide, polysulfone, polyarylate, polyethylene terephthalate, polybutylene terephthalate, polyoxymethylene, polycarbonate, polypropylene, polyethylene, poly Any one or more of methyl methacrylate may be included.

The nonwoven fabric substrate layer may have a thickness of 5 μm to 100 μm, and the porous structure layer may have a thickness of 5 μm to 500 μm.

The first electrode or the second electrode may include a solid electrolyte, and the solid-liquid hybrid electrolyte membrane may have a thickness of 10-50 μm.

The solid-liquid hybrid electrolyte membrane may have a mechanical strength of 500 kgf/cm ² to 5000 kgf/cm ² .

The solid-liquid hybrid electrolyte membrane may have a thickness of 5 μm to 500 μm.

The lithium secondary battery may be a lithium ion secondary battery or an all solid state battery.

The first electrode and the second electrode may each independently contain or not contain a solid electrolyte.

The porous structure layer may be directly and independently coated on the first electrode or the second electrode.

Another aspect of the present invention provides a method of manufacturing a lithium secondary battery according to the following embodiments.

in particular,
A method for manufacturing a lithium secondary battery comprising a first electrode and a second electrode having opposite polarities and a solid-liquid hybrid electrolyte membrane interposed between the first electrode and the second electrode, the method comprising:
(S1) preparing a dispersion containing solid polymer particles and a liquid electrolyte;
(S2) coating the dispersion on the first electrode to form a porous structure layer;
(S3) A non-woven fabric substrate and a second electrode having a polarity opposite to that of the first electrode are sequentially laminated on the porous structure layer and pressed to form a solid-liquid hybrid electrolyte membrane including the non-woven fabric substrate layer. manufacturing;
The content of the liquid electrolyte is 50% to 70% with respect to 100% by weight of the total content of the solid-liquid hybrid electrolyte membrane.

The first electrode may be a positive electrode and the second electrode may be a negative electrode, or the first electrode may be a negative electrode and the second electrode may be a positive electrode.

The nonwoven fabric substrate layer has a microporous structure formed by a microstructure of polymer fibrils, and solid polymer particles are dispersed in the microporous structure or impregnated with the liquid electrolyte, The porous structure layer is in a state in which the solid polymer particles are filled and are in contact with each other, and a pore structure is formed between the solid polymer particles, and the liquid electrolyte is applied between the solid polymer particles. It can be the contact portion or the one surrounding the surface of the solid polymer particles.

The non-woven fabric base layer includes polyolefin, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyester, nylon, polyimide, polybenzoxazole, polytetrafluoroethylene, polyarylene ether sulfone, polyether ether ketone and these. It may contain one or a mixture of two or more selected from the group consisting of copolymers.

The solid polymer particles may be engineering plastic resins.

Said liquid electrolyte is a salt having a structure such as A ⁺ B ⁻ , where A ⁺ comprises alkali metal cations or ions consisting of combinations thereof, and B ⁻ is PF ₆ ⁻ , BF ₄ ⁻ , Cl ⁻ , Br ^- , I ^- , ClO ₄ ^- , AsF ₆ ^- , CH ₃ CO ₂ ^- , CF ₃ SO ₃ ^- , N(CF ₃ SO ₂ ) ₂ ^- , C(CF ₂ SO ₂ ) ₃ ^- or combinations thereof It can be a salt containing ions.

The lithium secondary battery may be a lithium ion secondary battery or an all solid state battery.

The first electrode and the second electrode may each independently contain or not contain a solid electrolyte.

According to one aspect of the present invention, it is possible to provide a lithium secondary battery including a deformable solid-liquid phase hybrid electrolyte membrane by using solid polymer particles instead of inorganic particles.

Also, it is possible to provide a lithium secondary battery including a solid-liquid hybrid electrolyte membrane with improved mechanical strength by using a polymer in the form of compressible particles. Since no solid electrolyte is used, a solid-liquid hybrid electrolyte membrane that can be deformed by external pressure can be provided. Also, the polymer particles are physically bonded together, which is advantageous for porosity and pore channel formation.

According to one aspect of the present invention, since no binder polymer is used, a solid-liquid hybrid electrolyte membrane with low resistance can be provided.

In addition, ionic conductivity is high by containing a certain amount of liquid electrolyte, and mechanical strength is high by using a nonwoven fabric base material, and ionic conductivity is improved by impregnating the nonwoven fabric base material with liquid electrolyte. A lithium secondary battery including a solid-liquid hybrid electrolyte membrane can be provided.

The drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further understand the technical idea of the present invention together with the content of the present invention. shall not be construed as being limited only to the matters described in . On the other hand, the shapes, sizes, scales or proportions of elements in the drawings attached to this specification may be exaggerated to emphasize a clearer description.

1 is a schematic diagram of a solid-liquid hybrid electrolyte membrane according to an embodiment of the present invention; FIG. 1 is a diagram schematically showing the structure of an all-solid-state battery including a solid-liquid hybrid electrolyte membrane according to an embodiment of the present invention; FIG. 1 is a diagram schematically showing a method of manufacturing a lithium secondary battery including a solid-liquid hybrid electrolyte membrane according to an embodiment of the present invention; FIG. 1 is a diagram schematically showing a method of manufacturing a lithium secondary battery including a solid-liquid hybrid electrolyte membrane according to an embodiment of the present invention; FIG. 1 is a diagram schematically showing a method of manufacturing a lithium secondary battery including a solid-liquid hybrid electrolyte membrane according to an embodiment of the present invention; FIG.

Hereinafter, embodiments of the present invention will be described in detail. Prior to this, the terms and words used in the specification and claims should not be construed as being limited to their ordinary or dictionary meaning, and the inventors themselves should explain their invention in the best possible way. Therefore, it should be interpreted with the meaning and concept according to the technical idea of the present invention according to the principle that the concept of the term can be properly defined. Therefore, the configuration shown in the embodiment described in this specification is merely one of the most desirable embodiments of the present invention, and does not represent all the technical ideas of the present invention. It should be understood that there may be various equivalents and modifications which may be substituted for them at the time.

Throughout this specification, when a part "includes" other components, it means that it can further include other components, rather than exclude other components, unless specifically stated otherwise.

Also, as used throughout this specification, the terms "about," "substantially," and the like are used at or near the numerical value when manufacturing and material tolerances inherent in the referenced meaning are presented. It is used as a semantic and to prevent unscrupulous infringers from exploiting disclosures in which exact or absolute numbers are referred to to aid understanding of the present application.

Throughout this specification, references to "A and/or B" mean "A, B, or all of these."

Certain terminology in the detailed description is used for convenience and is not limiting. The words "right", "left", "top" and "bottom" indicate directions in the drawings to which reference is made. The words "inwardly" and "outwardly" refer to directions toward and away from, respectively, the geometric center of the designated device, system, and components thereof. "Forward", "rearward", "upper", "lower" and related words and phrases are descriptive of position and orientation in the drawings to which reference is made and are not limiting. Such terms include the words above, derivatives thereof and words of similar import.

TECHNICAL FIELD The present invention relates to a lithium secondary battery including a solid-liquid hybrid electrolyte membrane and a manufacturing method thereof.

Specifically, the lithium secondary battery according to one aspect of the present invention comprises
a first electrode and a second electrode having opposite polarities, and a solid-liquid hybrid electrolyte membrane interposed between the first electrode and the second electrode;
At this time, the solid-liquid hybrid electrolyte membrane includes a non-woven fabric substrate layer and a porous structure layer, and contains a predetermined amount of liquid electrolyte.

At this time, the nonwoven fabric substrate layer has a microporous structure formed by a microstructure of polymer fibrils, and solid polymer particles are dispersed in the microporous structure or impregnated with the liquid electrolyte. ,
The porous structure layer is in a state in which the solid polymer particles are filled and are in contact with each other, and a pore structure is formed between the solid polymer particles. surrounding the surface contact portion, or a part or the entire surface of the solid polymer particle,
The content of the liquid electrolyte is 50% to 70% by weight with respect to 100% by weight of the total content of the solid polymer particles and the liquid electrolyte.

FIG. 1 schematically illustrates the structure of a solid-liquid hybrid electrolyte membrane according to an embodiment of the present invention, and FIG. 2 includes a solid-liquid hybrid electrolyte membrane according to an embodiment of the present invention. 3a to 3c schematically show a structure of an all-solid-state battery, and FIGS. 3a to 3c schematically show a method of manufacturing a lithium secondary battery including a solid-liquid hybrid electrolyte membrane according to an embodiment of the present invention; FIG. It is a diagram. The present invention will be described in more detail below with reference to the drawings.

Referring to FIG. 1, in one embodiment of the present invention, a solid-liquid hybrid electrolyte membrane 100 includes a nonwoven substrate layer 110 and a porous structural layer 120 .

The nonwoven fabric substrate layer 110 includes a nonwoven fabric substrate in which a microporous structure is formed by a microstructure of polymer fibrils.

At this time, the microporous structure is dispersed with solid polymer particles or impregnated with the liquid electrolyte. In other words, the polymer fibrils and the solid polymer particles are entangled, and the surfaces of the polymer fibrils and/or the surfaces of the solid polymer particles are coated with the liquid electrolyte.

In the present invention, the "polymer fibril" means that the polymer chains constituting the nonwoven fabric substrate layer are stretched and oriented in the longitudinal direction during the manufacturing process of the nonwoven fabric, and the binding force between adjacent molecular chains is increased. It means a structure formed by gathering together in the longitudinal direction.

The nonwoven fabric substrate layer may be a layered layer in which a plurality of polymer fibrils are arranged regularly or irregularly.

Thus, in one embodiment of the present invention, the solid-liquid hybrid electrolyte membrane includes a nonwoven fabric base layer, and the nonwoven base layer contains solid polymer particles or a liquid electrolyte to increase mechanical strength. can increase and improve ionic conductivity.

At this time, the polymer fibrils are polyolefin, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyester, nylon, polyimide, polybenzoxazole, polytetrafluoroethylene, polyarylene ether sulfone, polyether ether ketone, These copolymers or mixtures thereof may be used, but are not limited to these.

Specific examples of polyolefins include low-density polyethylene, high-density polyethylene, and linear low-density polyethylene, including polyethylene produced by copolymerizing ethylene with one or more C ₃ -C ₁₂ alpha olefins. polyethylene, such as polyethylene; and polypropylene, such as isotactic polypropylene, atactic polypropylene, syndiotactic polypropylene, but are not limited thereto. Polyolefin is a material that is widely used in the manufacture of secondary battery separator substrates.

Since the solid polymer particles are dispersed in the pores formed by the polymer fibrils, the mechanical strength can be further increased compared to the conventional case where only the polymer fibrils themselves or a solid electrolyte exists. . In addition, since the liquid electrolyte is impregnated in the microporous structure formed by the microstructure of the polymer fibrils, adverse effects such as increase in resistance can be minimized and ionic conductivity can be increased.

The polymer fibrils may have an average diameter of 0.005 μm to 5 μm, within the above numerical range, the mechanical strength of the nonwoven substrate layer is not reduced, and the porosity and thickness of the nonwoven substrate layer are reduced. Can be easily adjusted.

Nonwoven substrates made with such polymeric fibrils can have pores with an average diameter of 0.05 μm to 100 μm. If the nonwoven fabric substrate in the nonwoven fabric substrate layer satisfies the above numerical range of pore diameters, the desired ionic conductivity and Provides mechanical strength.

Alternatively, the pore size of the microporous structure in the nonwoven fabric substrate is 0.2 to 100 times, 0.5 to 80 times the average diameter (D ₅₀ ) of the solid polymer particles in the form of particles, or It can be from 1x to 50x. Within the above numerical range, the solid polymer particles are easily bound in the pores of the nonwoven fabric, and the short circuit occurrence rate after manufacturing the electrode assembly can be reduced.

Also, the nonwoven substrate may have a porosity ranging from 40% to 95%. The unit % of the porosity means vol % unless otherwise specified. If the nonwoven fabric substrate satisfies the above numerical range of porosity, even when the nonwoven fabric substrate is used for a solid-liquid phase hybrid electrolyte membrane, the desired ionic conductivity, mechanical strength and morphology can be achieved. Provides stability.

The "pores" in the present invention have various forms of pore structures and are measured using porosimeter or on FE-SEM (Field Emission Scanning Electron Microscope). If at least one of the average pore sizes observed in 1 satisfies the above conditions, it is included in the present invention.

In one specific embodiment of the invention, the thickness of said nonwoven substrate layer can be from 5 μm to 100 μm, from 8 μm to 75 μm or from 10 μm to 50 μm. In one embodiment of the present invention, providing a nonwoven fabric base layer having a thickness of 15 μm to 40 μm is advantageous in ensuring strength and ionic conductivity.

The porous structure layer 120 is in a state in which the solid polymer particles 12 are filled and in contact with each other, and a pore structure is formed between the solid polymer particles.

At this time, the solid polymer particles may be filled and brought into contact with each other by an external pressure. For example, the external pressure may be uniaxial pressure, roll press, cold isostatic press (CIP), hot isostatic press (HIP), and the like. However, without being limited to these, any physical or chemical method capable of adhering the solid polymer particles can be used.

At this time, the solid polymer particles are plastically deformed beyond the physical elastic region of the particles by the external pressure described above, and the contact surface between the particles increases or the volume increases compared to before the pressure is applied. New contact surfaces may be formed by change, or the adhesion of the adhesive surfaces between the particles may be increased by plastic deformation to form the desired structure. For example, solid polymeric particles can be pelletized.

The solid polymer particles are polymer substances that are solid at room temperature and have low solubility in an electrolytic solution. In the present invention, the solid polymer particles are preferably surrounded by a liquid electrolyte and have low solubility in the liquid electrolyte. Moreover, it is desirable that the polymer be excellent in chemical resistance.

Specifically, the solid polymer particles have a solubility of less than 30% when impregnated with a liquid electrolyte such as ethylene carbonate:ethyl methyl carbonate=30:70 (volume %). More specifically, it may have a solubility of less than 20%, less than 15% or less than 10%. Thereby, the solid polymer particles can exist in a solid state even when dispersed in a solvent.

Specifically, the solid polymer particles may be engineering plastic resins.

At this time, the engineering plastic resin is selected from polyphenylene sulfide, polyetheretherketone, polyimide, polyamideimide, liquid crystal polymer, polyetherimide, polysulfone, polyarylate, polybutylene terephthalate, polyoxymethylene, polycarbonate, and polymethyl methacrylate. Any one or two or more may be included. At this time, the engineering plastic resin may have a molecular weight of 100,000 Da to 10,000,000 Da.

The solid polymer particles have compressibility unlike general commercial inorganic particles. Accordingly, it is possible to provide a lithium secondary battery having an increased energy density per weight relative to the thickness. In addition, by using solid polymer particles instead of conventional solid electrolytes, it is possible to provide a deformable solid-liquid hybrid electrolyte membrane. Such solid polymeric particles are ductile and can be physically or chemically linked by pressure or heat. Accordingly, the solid-liquid hybrid electrolyte membrane according to an embodiment of the present invention does not require a separate binder polymer. That is, the solid-liquid hybrid electrolyte membrane does not contain a binder polymer. This makes it possible to provide a solid-liquid hybrid electrolyte membrane with reduced resistance.

In one specific embodiment of the present invention, the solid polymer particles may have an average particle size of 100 nm to 10 μm, 200 nm to 5 μm or 500 nm to 2 μm. By controlling the particle diameter within the above numerical range, pores of an appropriate size are formed to prevent short circuits and allow sufficient impregnation with the liquid electrolyte.

The present invention includes a quantity of liquid electrolyte 13 through which lithium ions can be transferred. That is, one embodiment of the present invention can provide a lithium secondary battery including a solid-liquid hybrid electrolyte membrane with high ionic conductivity without using a solid electrolyte.

The liquid electrolyte is present in the portions where the solid polymer particles are in surface contact with each other, or surrounds the surfaces of the solid polymer particles. In other words, the liquid electrolyte can coat the surfaces of the solid polymer particles. The presence of such a liquid electrolyte makes it possible to provide a solid-liquid hybrid electrolyte membrane with high ionic conductivity.

The content of the liquid electrolyte is 50 wt % to 70 wt % with respect to 100 wt % of the total content of the solid polymer particles and the liquid electrolyte. Specifically, the content of the liquid electrolyte may be 50% by weight or more, 55% by weight or more, or 60% by weight or more based on the total content of the solid polymer particles and the liquid electrolyte. and the liquid electrolyte may be 70% by weight or less, 68% by weight or less, or 65% by weight or less. Such a high liquid electrolyte content can improve the ionic conductivity of the solid-liquid hybrid electrolyte membrane.

In one embodiment of the invention, the solid-liquid hybrid electrolyte membrane has high ionic conductivity. This is because the liquid electrolyte is uniformly dispersed on the surfaces of the solid polymer particles or on the surface-contacting portions. In one embodiment of the present invention, one or more suitable coating methods such as dip coating, spray coating, doctor blade coating, or drop coating are selected to uniformly impregnate the liquid electrolyte. and is not limited to any particular method.

In a specific embodiment of the present invention, the liquid electrolyte does not dissolve the solid polymer particles and has excellent chemical resistance and electrochemical resistance.

For example, the liquid electrolyte is a salt with a structure such as A ⁺ B ^- , where A ⁺ includes ions consisting of alkali metal cations or combinations thereof, such as Li ⁺ , Na ⁺ , K ⁺ etc., and B ^— is PF ₆ ⁻ , BF ₄ ⁻ , Cl ⁻ , Br ⁻ , I ⁻ , ClO ₄ ⁻ , AsF ₆ ⁻ , CH ₃ CO ₂ ⁻ , CF ₃ SO ₃ ⁻ , N(CF ₃ SO ₂ ) ₂ ⁻ , C Salts containing anions such as (CF ₂ SO ₂ ) ₃ ^- or ions consisting of a combination of these may be dissolved or dissociated in organic solvents such as ethers, carbonates and nitriles. is not limited to

For example, the ether-based organic solvent may include dimethyl ether, diethyl ether, dipropyl ether, methyl ethyl ether, methyl propyl ether, ethyl propyl ether, 1,2-dimethoxyethane, or a mixture of two or more thereof.

For example, the carbonate-based organic solvent may be propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), ethyl methyl carbonate (EMC), or these It may contain a mixture of two or more of them.

For example, the nitrile-based organic solvent may include acetonitrile, succinonitrile, or a mixture of two or more thereof.

Other organic solvents may include, but are not limited to, dimethylsulfoxide, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), γ-butyrolactone, or mixtures thereof.

In a specific embodiment of the present invention, the ionic conductivity of the solid-liquid hybrid electrolyte membrane is greater than the ionic conductivity of the porous structure layer itself, 1×10 ⁻⁵ to 1×10 ⁻¹ S/cm, 1×10 ⁻⁴ to 1×10 ⁻² S/cm, or 1×10 ⁻⁴ to 5×10 ⁻³ S/cm.

As described above, in the solid-liquid hybrid electrolyte membrane according to an embodiment of the present invention, the porosity of the electrolyte membrane is smaller than that of the porous structure layer, but the ion conductivity is higher than that of the porous structure layer itself. can have

In a specific embodiment of the present invention, the porous structure layer can be directly and independently formed on the first electrode or the second electrode.

At this time, the forming method is not limited, and may be formed by a method commonly used in the art.

For example, it can be manufactured by coating a dispersion containing solid polymer particles and a liquid electrolyte on the first electrode or the second electrode.

The solid polymer particles according to an embodiment of the present invention are present in a form in which the liquid electrolyte surrounds the solid polymer particles, so that a solid-liquid hybrid electrolyte membrane is formed in the finally manufactured lithium secondary battery. Ionic conductivity can be increased.

At this time, the dispersion liquid is overcoated on the first electrode or the second electrode to form a porous structure layer, and then a nonwoven fabric substrate is interposed to form a nonwoven fabric substrate. A nonwoven substrate layer impregnated with solid polymeric particles and/or a liquid electrolyte between the molecular fibrils may be formed.

In a specific embodiment of the present invention, the porosity and pore size of the porous structure layer itself and the electrolyte membrane are determined according to the average particle size of the solid polymer particles used or the pressure conditions during production. It can be adjusted by controlling. For example, it can be adjusted by adjusting the roll gap of the roll press, controlling the production temperature, or controlling the content or particle size of the solid polymer particles.

In one specific embodiment of the present invention, the thickness of said porous structure layer may be 5 μm to 500 μm, 20 μm to 300 μm or 30 μm to 100 μm. In one embodiment of the present invention, the use of a thin porous structure layer, such as 10 μm to 50 μm, is advantageous in terms of energy density when subsequent batteries are manufactured.

In one specific embodiment of the present invention, the solid-liquid hybrid electrolyte membrane may have a thickness of 5 μm to 500 μm, 20 μm to 300 μm or 30 μm to 100 μm. An embodiment of the present invention can provide a thin solid-liquid hybrid electrolyte membrane having a thickness of 10 μm to 50 μm, which is advantageous in terms of energy density when a battery is subsequently manufactured.

In a specific embodiment of the present invention, the solid-liquid hybrid membrane has a tensile strength of 500 kgf/cm ² to 5000 kgf/cm ² , 700 kgf/cm ² to 3000 kgf/cm ² or 1000 kgf/cm ² to about It can be 2000 kgf/cm ² .

In one specific embodiment of the present invention, the lithium secondary battery may be a lithium ion battery or an all solid state battery.

Specifically, the first electrode and the second electrode may each independently contain or not contain a solid electrolyte.

At this time, the first electrode may be a positive electrode and the second electrode may be a negative electrode, or the first electrode may be a negative electrode and the second electrode may be a positive electrode.

In the present invention, the positive electrode and the negative electrode have a current collector and an electrode active material layer formed on at least one surface of the current collector, the active material layer including a plurality of electrode active material particles, and optionally It may contain a solid electrolyte. Also, the electrode may further include one or more of a conductive material and a binder resin, if necessary. Also, the electrode may further include various additives for the purpose of complementing or improving the physicochemical properties of the electrode.

In the present invention, the negative electrode active material can be used without limitation as long as it can be used as a negative electrode active material for lithium ion secondary batteries. For example, _the negative _electrode active material includes carbon such _as non-graphitizable carbon and graphitic carbon; _LixFe2O3 (0≤x≤1), _{LixWO2 (} 0≤x≤1), _{SnxMe1 -x} Me ^' _y O _z (Me: Mn, Fe, Pb, Ge; Me ^' : Al, B, P, Si, elements of Groups 1, 2, and 3 of the periodic table, halogen; 0 < x ≤ 1; 1 ≤ y ≤ 3; 1 ≤ z ≤ 8 _{) metal} composite oxides; lithium _metal ; lithium alloys; silicon-based alloys; tin- _based alloys _; metal oxides such _{as O4} , _{Sb2O3 , Sb2O4 , Sb2O5} , GeO, _GeO2 , _{Bi2O3 , Bi2O4} and _Bi2O5 ; conductive polymers _{such as} polyacetylene; Li--Co--Ni based materials; titanium oxides; lithium titanium oxides, or the like. In one specific embodiment, the negative active material may include a carbon-based material and/or Si.

In the case of the positive electrode, the electrode active material can be used without limitation as long as it can be used as a positive electrode active material for lithium ion secondary batteries. For example, the cathode active material may be a layered compound such as lithium cobalt oxide ( _LiCoO2 ) or lithium nickel oxide ( _LiNiO2 ), or a compound substituted with one _or more transition metals; Lithium manganese oxides such as _2-x O ₄ (where x is 0 to 0.33), LiMnO ₃ , LiMn ₂ O ₃ , LiMnO ₂ ; Lithium copper oxide (Li ₂ CuO ₂ ); LiV ₃ O ₈ , LiV ₃ Vanadium oxides such as O ₄ , V ₂ O ₅ , Cu ₂ V ₂ O ₇ ; chemical formula LiNi _1-x M _x O ₂ (M=Co, Mn, Al, Cu, Fe, Mg, B or Ga, x= _0.01 to 0.3) Ni-site _{type lithium} nickel oxide; 0.1) or lithium-manganese composite oxide represented by Li ₂ Mn ₃ MO ₈ (M=Fe, Co, Ni, Cu or Zn); spinel-structured lithium represented by LiNi _x Mn _2-x O ₄ Manganese composite oxides; LiMn ₂ O ₄ in which part of Li in the chemical formula is substituted with alkaline earth metal ions; disulfide compounds; Fe ₂ (MoO ₄ ) ₃ , etc., but not limited to .

In the present invention, as the current collector, a current collector known in the secondary battery field having electrical conductivity, such as a metal plate, may be appropriately used according to the polarity of the electrode.

In the present invention, the conductive material is generally added in an amount of 1-30% by weight based on the total weight of the mixture containing the electrode active material. Such a conductive material is not particularly limited as long as it does not induce a chemical change in the battery and has conductivity, for example, graphite such as natural graphite and artificial graphite; carbon black, acetylene black, ketjen black Carbon blacks such as , channel black, furnace black, lamp black, thermal black; Conductive fibers such as carbon fiber and metal fiber; Metal powder such as carbon fluoride, aluminum and nickel powder; Zinc oxide, potassium titanate etc. It may contain one or a mixture of two or more selected from conductive whiskers; conductive metal oxides such as titanium oxide; and conductive materials such as polyphenylene derivatives.

In the present invention, the binder resin is not particularly limited as long as it is a component that assists the bonding between the active material and the conductive material, and the bonding to the current collector. Examples include polyvinylidene fluoride, polyvinyl alcohol, and carboxymethyl cellulose (CMC). , starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene monomer (EPDM), sulfonated EPDM, styrene-butadiene rubber, fluororubber, various copolymers, etc. be done. The binder resin may generally be contained in the range of 1 to 30% by weight or 1 to 10% by weight with respect to 100% by weight of the electrode layer.

Meanwhile, in the present invention, the electrode active material layer may contain one kind of additive such as an oxidation stabilizer additive, a reduction stabilizer additive, a flame retardant, a heat stabilizer, an antifogging agent, etc., if necessary. can include more than

In the present invention, the solid electrolyte may further include one or more of a polymer-based solid electrolyte, an oxide-based solid electrolyte, and a sulfide-based solid electrolyte.

In the present invention, the solid electrolyte may be different for the positive electrode and the negative electrode, or may be the same for two or more battery elements. For example, in the case of the positive electrode, a polymer electrolyte having excellent oxidation stability can be used as the solid electrolyte. Moreover, in the case of the negative electrode, it is desirable to use a polymer electrolyte excellent in reduction stability as a solid electrolyte. However, the present invention is not limited to these materials, and a material having high ion conductivity, such as 10 ⁻⁷ S/m or more or 10 ⁻⁵ S/m or more, is used to mainly transfer lithium ions in the electrode. Any component can be used as long as it is used, and the component is not limited to a specific one.

In the present invention, each of the polymer electrolytes is independently a solid polymer electrolyte formed by adding a polymer resin to a solvated lithium salt, or an organic electrolyte containing an organic solvent and a lithium salt. It may be a polymer gel electrolyte in which a liquid is contained in a polymer resin.

The present invention also provides a secondary battery having the structure described above. The present invention also provides a battery module including the secondary battery as a unit battery, a battery pack including the battery module, and a device including the battery pack as a power source. At this time, specific examples of the device include a power tool driven by an electric motor; an electric vehicle (EV), a hybrid electric vehicle (HEV), and a plug-in hybrid electric vehicle. Electric vehicles including (Plug-in Hybrid Electric Vehicle: PHEV), etc.; electric bicycles (E-bike), electric scooters (E-scooter) including electric motorcycles; electric golf carts; It is not limited to these.

One aspect of the present invention provides a method of manufacturing a lithium secondary battery according to the following embodiments. Each step is shown schematically in FIGS. 3a-3c.

First, (S1) a dispersion containing a large number of solid polymer particles and a liquid electrolyte is prepared (S1). The steps are shown in FIG. 3a. At this time, solid polymer particle powder can be used as the polymer particles. Alternatively, a dispersion can be used in which a large number of polymeric particles are dispersed in a liquid electrolyte. At this time, the polymer particles are as described in the solid polymer particles described above. At this time, the solvent does not dissolve the solid polymer particles but can disperse them. For example, it can be ethanol, methanol, and the like.

Meanwhile, the content of the liquid electrolyte is 50 wt % to 70 wt % with respect to 100 wt % of the total content of the solid polymer particles and the liquid electrolyte. Specifically, the content of the liquid electrolyte may be 50% by weight or more, 55% by weight or more, or 60% by weight or more based on the total content of the solid polymer particles and the liquid electrolyte. It may be 70 wt% or less, 68 wt% or less, or 65 wt% or less of the total content with the liquid electrolyte. Such a high liquid electrolyte content can improve the ionic conductivity of the solid-liquid hybrid electrolyte membrane.

In a specific embodiment of the present invention, the dispersion in step (S1) may further include a separate solvent for dispersion. Non-limiting examples of solvents include, but are not limited to, acetone, tetrahydrofuran, methylene chloride, and the like.

Next, the dispersion is applied on the first electrode to form a porous structure layer (S2). At this time, the first electrode may be a positive electrode or a negative electrode, and the second electrode, which will be described later, may be an electrode having a polarity opposite to that of the first electrode and may be a negative electrode or a positive electrode.

At this time, the application can be carried out using a normal method available in the industry. The steps are shown in FIG. 3b. As shown in FIG. 3b, in order to uniformly coat the polymer particles on the nonwoven fabric substrate 11, a method of dispersing the polymer particles in a liquid electrolyte and then coating the dispersion may be used. In this case, the solid polymer particles may form a porous structure layer through the pressing step. At this time, the solid polymer particles can be physically bonded by applying pressure or heat, and no additional binder polymer is required.

In addition, according to the present invention, a separate drying step is not required when forming the porous structure layer.

In the present invention, a high content of liquid electrolyte is used to increase the ionic conductivity of the solid-liquid hybrid membrane. In order to solve the mechanical strength, structural morphology maintenance, and process problems caused by the use of a high content of liquid electrolyte, in the present invention, the nonwoven fabric substrate is immediately applied after the dispersion is applied on the electrode. intervene. As a result, it is possible to manufacture a solid-liquid phase hybrid membrane that eliminates leakage of the liquid electrolyte and solves the above-described problems. In other words, in the case of the present invention, the step of interposing the nonwoven substrate is included instead of having a separate drying step because the liquid electrolyte must be maintained at a high content.

Thereafter, a non-woven fabric substrate and a second electrode having a polarity opposite to that of the first electrode are sequentially laminated on the porous structure layer and pressed to manufacture a solid-liquid hybrid electrolyte membrane including the non-woven fabric substrate layer. (S3).

Specifically, in the step S3, after laminating a non-woven fabric substrate on the porous structure layer, an electrode assembly is formed by sequentially laminating a first electrode, a porous structure layer, a non-woven fabric substrate, and a second electrode. This is the step of applying pressure. As a result, a nonwoven fabric substrate layer in which solid polymer particles are dispersed or impregnated with the liquid electrolyte in the fine pore structure of the nonwoven fabric substrate can be formed.

At this time, the pressing step is performed once or several times at predetermined intervals in order to control the thickness and porosity of the porous substrate layer and/or the solid-liquid hybrid electrolyte membrane. can be stages.

A lithium secondary battery having a solid-liquid hybrid electrolyte membrane including a porous structure layer and a non-woven fabric substrate layer can be manufactured by the above manufacturing method.

In a specific embodiment of the present invention, the first electrode may be a positive electrode and the second electrode may be a negative electrode, or the first electrode may be a negative electrode and the second electrode may be a positive electrode. .

In addition, the nonwoven fabric base layer has a microporous structure formed by a microstructure of polymer fibrils, and the solid polymer particles are dispersed in the microporous structure or impregnated with the liquid electrolyte. ing.

In a specific embodiment of the present invention, the porous structure layer is filled with the solid polymer particles and is in contact with each other, and a pore structure is formed between the solid polymer particles, The liquid electrolyte surrounds the portions where the solid polymer particles are in surface contact with each other or the surfaces of the solid polymer particles.

At this time, the non-woven fabric base layer is made of polyolefin, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyester, nylon, polyimide, polybenzoxazole, polytetrafluoroethylene, polyarylene ether sulfone, polyether ether ketone. and a nonwoven fabric substrate containing one or a mixture of two or more selected from the group consisting of these copolymers.

The solid polymer particles may be engineering plastic resins. For details, refer to the above description.

Said liquid electrolyte is a salt having a structure such as A ⁺ B ⁻ , where A ⁺ comprises alkali metal cations or ions consisting of combinations thereof, and B ⁻ is PF ₆ ⁻ , BF ₄ ⁻ , Cl ⁻ , Br ^- , I ^- , ClO ₄ ^- , AsF ₆ ^- , CH ₃ CO ₂ ^- , CF ₃ SO ₃ ^- , N(CF ₃ SO ₂ ) ₂ ^- , C(CF ₂ SO ₂ ) ₃ ^- or combinations thereof It can be a salt containing ions, but is not limited to these.

The first electrode and the second electrode may each independently contain or not contain a solid electrolyte.

The porous structure layer may be directly and independently coated on the first electrode or the second electrode.

A method for manufacturing a lithium secondary battery according to an embodiment of the present invention applies the dispersion liquid directly onto the electrode as described above. The dispersion contains solid polymer particles and a liquid electrolyte, and the content of the liquid electrolyte is the same as or greater than the content of the solid polymer particles. Therefore, when a separate free-standing separation membrane is manufactured using the dispersion, the contained liquid electrolyte may leak, and the high liquid electrolyte content makes it difficult to maintain mechanical strength. Moreover, when the nonwoven fabric base material is directly coated, the nonwoven fabric base material has large pores, so the liquid electrolyte may not be impregnated and may disappear. On the other hand, according to one embodiment of the present invention, the dispersion can be applied directly onto the electrode to ensure sufficient ionic conductivity, reduce short circuits, and increase mechanical strength.

EXAMPLES The present invention will be described in more detail below with reference to Examples, but the Examples below are intended to illustrate the present invention, and the scope of the present invention is not limited thereto.

Example 1
NCM811 (LiNi _0.8 Co _0.1 Mn _0.1 O ₂ ) as a positive electrode active material and VGCF (vapor grown carbon fiber) as a conductive material were used to prepare a positive electrode forming slurry. and polymer solid electrolyte (PEO (polyethylene oxide) + LiTFSI (lithium bis(trifluoromethane)sulfonimide), [EO]/[Li ⁺ ] = 18:1 (molar ratio)) at a weight ratio of 80:3:17. Manufactured by This was applied to an aluminum current collector having a thickness of 20 μm using a doctor blade, and the resulting product was vacuum-dried at 120° C. for 4 hours. After that, the vacuum-dried product was subjected to a rolling process using a roll press, and a positive electrode slurry of 3 mAh/cm ² based on the area of the electrode was loaded to obtain a positive electrode having a porosity of 22%.

On the other hand, as solid polymer particles, powdery polyphenylene sulfide (average particle size: 10 µm) was mixed with a liquid electrolyte (ethylene carbonate:ethyl methyl carbonate = 3:7 (vol%), LiPF ₆ 1M, vinylene carbonate 0.5 volume. %, fluoroethylene carbonate 1% by volume) at a ratio of 50:50 (weight ratio) to prepare a dispersion.

3 ml of the dispersion was applied onto the positive electrode using a doctor blade and pressurized to form a porous structure layer. The thickness of the porous structural layer was about 94 μm. A 40 μm thick PET nonwoven fabric substrate (78% porosity) was laminated on the porous structure layer and punched out into a circle of 1.4875 cm ² . Then, after laminating lithium metal as a negative electrode so as to face the nonwoven fabric substrate, lamination is performed at room temperature by adjusting the roll press interval, thereby forming an all-solid battery including the porous structure layer and the nonwoven fabric substrate layer. manufactured.

The thickness of the solid-liquid hybrid electrolyte membrane containing the nonwoven fabric substrate layer was 58 μm.

Example 2
A solid-liquid phase hybrid electrolyte comprising a non-woven fabric substrate after lamination, wherein the ratio of the solid polymer particles and the liquid electrolyte is controlled to 30:70 (weight ratio), the thickness of the porous structure layer is controlled to 81 μm. An all-solid-state battery was manufactured in the same manner as in Example 1, except that the film thickness was 50 μm.

Example 3
The ratio of the solid polymer particles and the liquid electrolyte was controlled to 30:70 (weight ratio), the thickness of the porous structure layer was controlled to 77 μm, and the non-woven fabric base layer (porosity: 58%) with a thickness of 20 μm was prepared. An all-solid-state battery was manufactured in the same manner as in Example 1, except that the thickness of the solid-liquid phase hybrid electrolyte membrane after lamination was 43 μm.

Example 4
In order to prepare the slurry for negative electrode formation, artificial graphite as a negative electrode active material, VGCF as a conductive material and a polymer solid electrolyte (PEO + LiTFSI, [EO]/[Li ⁺ ] = 18:1 (molar ratio)) were mixed at 90%. : 2:8 weight ratio. This was applied to a copper current collector having a thickness of 15 μm using a doctor blade, and the resulting product was vacuum-dried at 100° C. for 6 hours. Thereafter, the vacuum-dried product was subjected to a rolling process using a roll press, and a negative electrode slurry of 3.3 mAh/cm ² was loaded to obtain a positive electrode having a porosity of 25%.

On the other hand, powdery polyphenylene sulfide (average particle size: 10 µm) was used as the solid polymer particles, and liquid electrolyte (ethylene carbonate: ethyl methyl carbonate = 3:7 (vol%), LiPF ₆ 1M, vinylene carbonate 0.5 vol% , fluoroethylene carbonate 1% by volume) at a ratio of 30:70 (weight ratio) to prepare a dispersion.

A porous structure layer was prepared by coating 3 ml of the dispersion on the negative electrode using a doctor blade. At this time, the thickness of the manufactured porous structure layer was about 82 μm. A 40 μm-thick PET nonwoven fabric substrate (78% porosity) was laminated on the porous structural layer, and it was punched out into a circle of 1.4875 cm ² . Thereafter, lithium metal is used as a counter electrode and laminated so as to face the non-woven fabric substrate, and lamination is performed at room temperature by adjusting the roll-pressing interval to manufacture an all-solid-state battery including a porous structure layer and a non-woven fabric substrate layer. bottom.

The thickness of the solid-liquid hybrid electrolyte membrane containing the non-woven fabric substrate was 52 μm.

Example 5
A lithium ion battery was manufactured by the following method.

First, NCM811 (LiNi _0.8 Co _0.1 Mn _0.1 O ₂ ) as a positive electrode active material, VGCF and polyvinylidene fluoride (PVDF) as a conductive material were prepared at a weight ratio of 95:3:2. This was applied to an aluminum current collector having a thickness of 20 μm using a doctor blade, and the resulting product was vacuum-dried at 120° C. for 4 hours. Then, the vacuum-dried product was subjected to a rolling process using a roll press, and a positive electrode slurry of 3 mAh/cm ² was loaded to obtain a positive electrode having a porosity of 22%.

Next, powdery polyphenylene sulfide (average particle size: 10 µm) was added as solid polymer particles to a liquid electrolyte (ethylene carbonate:ethyl methyl carbonate = 3:7 (% by volume), LiPF ₆ 1M, vinylene carbonate 0.5% by volume. , fluoroethylene carbonate 1% by volume) at a ratio of 30:70 (weight ratio) to prepare a dispersion.

A porous structure layer was formed by coating 3 ml of the dispersion on the positive electrode using a doctor blade. The thickness of the porous structural layer was about 94 μm. A 40 μm thick PET nonwoven fabric substrate (78% porosity) was laminated on the porous structure layer and punched out into a circle of 1.4875 cm ² . After that, lithium metal was used as a negative electrode, and after lamination facing the nonwoven fabric substrate, lamination was performed at room temperature by adjusting the roll-pressing interval to manufacture a lithium ion battery including a porous structure layer and a nonwoven fabric substrate layer. .

The thickness of the solid-liquid hybrid electrolyte membrane containing the nonwoven fabric substrate layer was 58 μm.

Comparative example 1
Prior to manufacturing the all-solid-state battery, a solid-liquid phase hybrid electrolyte membrane was manufactured by the following method, but the strength of the manufactured solid-liquid phase electrolyte membrane was not sufficient. was difficult to form and could not be removed from the release film.

Powdered polyphenylene sulfide (average particle size: 10 µm) as solid polymer particles was mixed with a liquid electrolyte (ethylene carbonate:ethyl methyl carbonate = 3:7 (vol%), LiPF ₆ 1M, vinylene carbonate 0.5vol%, fluoro A dispersion was prepared by dispersing in ethylene carbonate (1% by volume) at a ratio of 30:70 (weight ratio).

A solid-liquid hybrid electrolyte membrane was fabricated by coating 3 ml of the dispersion on a release film, not on an electrode, using a doctor blade. However, since the strength of the solid-liquid electrolyte membrane produced after coating was not sufficient, it was difficult to form a membrane structure and could not be removed from the release film.

Comparative example 2
Prior to manufacturing the all-solid-state battery, a solid-liquid phase hybrid electrolyte membrane was manufactured by the following method. Electrolyte membranes were difficult to fabricate because they either passed through and were transferred onto the other side of the nonwoven substrate or the surface was roughened.

In the case of Comparative Example 2, a solid-liquid phase hybrid electrolyte membrane was manufactured in the same manner as in Example 2, except that the porous structure layer was directly coated on the non-woven fabric instead of the electrode.

Specifically, 3 ml of the prepared dispersion was applied onto a 40 μm thick PET nonwoven fabric substrate (78% porosity) using a doctor blade.

In the case of Comparative Example 2, since the pores of the non-woven fabric substrate are large, the solid polymer particles pass through the pores in the non-woven fabric substrate and are transferred onto the other surface of the non-woven fabric substrate, or the surface becomes rough. It was difficult to fabricate the electrolyte membrane.

Comparative example 3
An all-solid-state battery was manufactured in the same manner as in Example 2, except that the nonwoven fabric substrate was not used.

Specifically, 3 ml of the prepared dispersion was applied onto the positive electrode using a doctor blade. At this time, the thickness of the manufactured porous structure layer was about 74 μm. After that, the porous structure layer was interposed between the positive electrode and the lithium metal negative electrode, and lamination was performed by adjusting the roll-pressing interval at room temperature to manufacture an all-solid-state battery. The thickness of the interposed porous structural layer was 42 μm.

Comparative example 4
Same as Example 2, except that a polyolefin separation membrane (thickness 9 μm, porosity 43%, pore size 200 nm) was used instead of the non-woven fabric substrate when producing the solid-liquid hybrid electrolyte membrane. An all-solid-state battery was manufactured by the method of

As shown in Table 1, when a dispersion containing easily deformable solid polymer particles is interposed between the positive electrode and the negative electrode together with the non-woven fabric substrate, sufficient strength as a separation membrane is ensured. The occurrence of micro-shorts was reduced, and ionic conductivity was secured.

On the other hand, in the case of Comparative Example 1, in which the solid-liquid hybrid membrane is manufactured alone without including the non-woven fabric substrate, it is difficult to manufacture the solid-liquid hybrid membrane, and the porous structure layer is formed directly on the electrode. However, in the case of Comparative Example 3, which did not include the non-woven fabric base layer, it was difficult to fabricate a battery due to the occurrence of micro-shorts.

When the dispersion is directly coated on the nonwoven fabric substrate as in Comparative Example 2, the pores of the nonwoven fabric substrate are large, so the solid polymer particles or the liquid electrolyte pass through the pores in the nonwoven fabric substrate. It was difficult to fabricate the electrolyte membrane because it was transferred onto the other surface of the substrate or the surface became rough.

In addition, as in Comparative Example 4, when a general polyolefin-based separation membrane is applied instead of a non-woven fabric substrate, the porosity of the polyolefin-based separation membrane is small or the pores are small. A structure different from the structure formed between and was formed, and performance degradation occurred due to small pores.

100: Solid phase-liquid phase hybrid electrolyte membrane 110: Non-woven fabric substrate layer 120: Porous structure layer 11: Polymer fibril 12: Solid polymer particles 13: Liquid electrolyte 200: All-solid battery 210: Positive electrode 220: Negative electrode 230: Solid phase-liquid phase hybrid electrolyte membrane 231: nonwoven fabric substrate layer 232: porous structure layer 21: polymer fibrils 22: solid polymer particles 23: liquid electrolyte

Claims (20)

A lithium secondary battery comprising a first electrode and a second electrode having opposite polarities, and a solid-liquid hybrid electrolyte membrane interposed between the first electrode and the second electrode,
The solid phase-liquid phase hybrid electrolyte membrane is
and a porous structure layer formed on at least one surface of the non-woven fabric substrate layer, wherein the non-woven fabric substrate layer has a microporous structure formed by a microstructure of polymer fibrils. , solid polymer particles dispersed in the microporous structure or impregnated with a liquid electrolyte,
The porous structure layer is in a state in which the solid polymer particles are filled and are in contact with each other, and a pore structure is formed between the solid polymer particles. surrounding the surface contact portion, or a part or the entire surface of the solid polymer particle,
The content of the liquid electrolyte is 50 to 70% by weight with respect to 100% by weight of the total content of the solid polymer particles and the liquid electrolyte,
A lithium secondary battery, wherein the ion conductivity of the solid-liquid phase hybrid electrolyte membrane is 1×10 ⁻⁵ to 1×10 ⁻¹ S/cm. the polymeric fibrils have an average diameter of 0.005 μm to 5 μm;
The lithium secondary battery according to claim 1, wherein the nonwoven fabric base layer has pores with a diameter of 0.05 µm to 30 µm and a porosity in the range of 50 to 80%. The polymer fibril is selected from the group consisting of polyolefin, polyethylene terephthalate, polyethylene naphthalate, polyester, nylon, polyimide, polybenzoxazole, polytetrafluoroethylene, polyarylene ether sulfone, polyether ether ketone and copolymers thereof. 3. The lithium secondary battery according to claim 1, which is a selected one or a mixture of two or more. 4. The lithium secondary battery according to claim 1, wherein said solid polymer particles are engineering plastic resin. The solid polymer particles include polyphenylene oxide, polyetheretherketone, polyimide, polyamideimide, liquid crystal polymer, polyetherimide, polysulfone, polyarylate, polyethylene terephthalate, polybutylene terephthalate, polyoxymethylene, polycarbonate, polypropylene, polyethylene, poly 5. The lithium secondary battery according to any one of claims 1 to 4, comprising any one or more of methyl methacrylate. The nonwoven fabric substrate layer has a thickness of 5 μm to 100 μm,
The lithium secondary battery according to any one of claims 1 to 5, wherein the porous structure layer has a thickness of 5 µm to 500 µm. The first electrode or the second electrode includes a solid electrolyte,
The lithium secondary battery according to any one of claims 1 to 6, wherein said solid-liquid phase hybrid electrolyte membrane has a thickness of 10 µm to 50 µm. 8. The lithium secondary battery according to claim 1, wherein the solid-liquid hybrid electrolyte membrane has a mechanical strength of 500 kgf/cm ² to 5000 kgf/cm ² . 6. The lithium secondary battery according to claim 1, wherein said solid-liquid phase hybrid electrolyte membrane has a thickness of 5 μm to 500 μm. The lithium secondary battery according to any one of claims 1 to 9, wherein said lithium secondary battery is a lithium ion secondary battery or an all solid state battery. 11. The lithium secondary battery according to claim 1, wherein said first electrode and said second electrode each independently contain or do not contain a solid electrolyte. 12. The lithium secondary battery according to any one of claims 1 to 11, wherein the porous structure layer is directly and independently coated on the first electrode or the second electrode. A method for manufacturing a lithium secondary battery comprising a first electrode and a second electrode having opposite polarities and a solid-liquid hybrid electrolyte membrane interposed between the first electrode and the second electrode, the method comprising:
(S1) preparing a dispersion containing solid polymer particles and a liquid electrolyte;
(S2) coating the dispersion on the first electrode to form a porous structure layer;
(S3) A non-woven fabric substrate and a second electrode having a polarity opposite to that of the first electrode are sequentially laminated on the porous structure layer and pressed to form a solid-liquid hybrid electrolyte membrane including the non-woven fabric substrate layer. manufacturing;
The method for manufacturing a lithium secondary battery, wherein the content of the liquid electrolyte is 50% to 70% with respect to 100% by weight of the total content of the solid-liquid hybrid electrolyte membrane. 14. The manufacture of a lithium secondary battery according to claim 13, wherein the first electrode is a positive electrode and the second electrode is a negative electrode, or the first electrode is a negative electrode and the second electrode is a positive electrode. Method. The nonwoven fabric substrate layer has a microporous structure formed by a microstructure of polymer fibrils, and solid polymer particles are dispersed in the microporous structure or impregnated with the liquid electrolyte,
The porous structure layer is in a state in which the solid polymer particles are filled and are in contact with each other, and a pore structure is formed between the solid polymer particles. 15. The method for producing a lithium secondary battery according to claim 13, wherein the surface contact portion or the surface of the solid polymer particles is surrounded. The nonwoven fabric base layer is a group consisting of polyolefin, polyethylene terephthalate, polyethylene naphthalate, polyester, nylon, polyimide, polybenzoxazole, polytetrafluoroethylene, polyarylene ether sulfone, polyether ether ketone and copolymers thereof. 16. The method for producing a lithium secondary battery according to any one of claims 13 to 15, comprising one or a mixture of two or more selected from. 17. The method for producing a lithium secondary battery according to claim 13, wherein said solid polymer particles are engineering plastic resin. Said liquid electrolyte is a salt having a structure such as A ⁺ B ⁻ , where A ⁺ comprises alkali metal cations or ions consisting of combinations thereof, and B ⁻ is PF ₆ ⁻ , BF ₄ ⁻ , Cl ⁻ , Br ^- , I ^- , ClO ₄ ^- , AsF ₆ ^- , CH ₃ CO ₂ ^- , CF ₃ SO ₃ ^- , N(CF ₃ SO ₂ ) ₂ ^- , C(CF ₂ SO ₂ ) ₃ ^- or combinations thereof 18. The method for producing a lithium secondary battery according to any one of claims 13 to 17, which is a salt containing ions. The method for manufacturing a lithium secondary battery according to any one of claims 13 to 18, wherein said lithium secondary battery is a lithium ion secondary battery or an all solid state battery. 20. The method of manufacturing a lithium secondary battery according to claim 13, wherein said first electrode and said second electrode each independently contain or do not contain a solid electrolyte.

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